Certain oximino phosphorus containing compounds, used as insecticides and acaricides

ABSTRACT

Compounds having the formula   in which X is oxygen or sulfur; Y is oxygen or sulfur; R is alkyl; R1 is alkyl; R2 is alkyl or alkoxy and R3 is (1) phenyl or (2) mono-, di- or tri-substituted phenyl wherein the substituent is (a) nitro, (b) cyano, (c) halogen,   wherein R4 is alkyl, (e) CF3, (f) SO2NHR5 wherein R5 is alkyl or (g) thiomethyl used as as insecticides and acaricides are disclosed.

United States Patent [1 1 Gutman [451 Sept. 23, 1975 CERTAIN OXIMINOPHOSPHORUS CONTAINING COMPOUNDS, USE!) AS INSECTICIDES AND ACARICIDES[75] Inventor: Arnold D. Gutman, Berkeley, Calif.

[73] Assignee: Stau ffer Chemical Company,

Westport, Conn.

22 Filed: June 12, 1912 21 Appl. No.: 261,860

Related U.S. Application Data [62] Division of Ser. No. 26,l03, April 6,1970,

[52] U.S. Cl 424/211; 424/2l0 [51] Int. Cl. AOIN 9/36 [58] Field ofSearch 424/210, 21 1; 260/944 [56] References Cited UNITED STATESPATENTS 3,663,664 5/1972 Retallick et a1 260/944 Primary ExaminerLeonardSchenkman Attorney, Agent, or Firm-Edwin H. Baker [57] ABSTRACTCompounds haying the formula if (d) C-R wherein R is alkyl, (e) CF (f)SO NHR wherein R is alkyl or (g) thiomethyl used as as insecticides andacaricides are disclosed.

8 Claims, No Drawings CERTAIN OXIMINO PI-IOSPI-IORUS CONTAININGCOMPOUNDS, USED AS INSECTICIDES AND ACARICIDES .This is a division, ofcopending application Ser. No. 26,103 filed Apr. 6, 1970.

This invention relates to certain novel chemical compounds, novelintermediates for their preparation, the use of the chemical compoundsas insecticides and acaricides and to a process for preparing theintermediates. More particularly, the chemical compounds are certainoximino phosphorus containing compounds.

The compounds of this invention are those having the formula in which Xis oxygen or sulfur; Y is oxygen or sulfur;

R is (1 alkyl having one to eight carbon atoms, preferably branchedchain or methyl, more preferably methyl and t-butyl;

R is alkyl having one to four carbon atoms, preferably methyl;

R is alkyl having one to four carbon atoms, preferably one to two carbonatoms; or alkoxy having one to four carbon atoms, preferably one to twocarbon atoms;

R is (l) phenyl or (21) mono-, dior tri-substituted phenyl wherein thesubstituent is (a) nitro, (b) cyano, (c) halogen, preferably chlorine,

wherein R is alkyl having one to four carbon atoms, preferably methyl,(e) CF (f) SO NHR wherein R is alkyl having one to four carbon atoms; or(g) thiomethyl, preferably mono substitution is in the meta or parapositions and the substituent is a halogen, nitro, thiomethyl, CF orcyano group, di substitution is meta and para or ortho and para and thesubstituents are both halogen groups and tri-substitution is in the2,4,5 position and the substituents are all halogen, preferablychlorine. Optionally, suchgroups as alkyl having one to four carbonatoms or (h) alkoxy having one to four carbon atoms can also besubstituted on the phenyl, preferably in the meta position.

The compounds of the present invention can be pre-- pared according tothe following reactions:

in which R, R', R-, R, x and Y are as defined.

The process of this invention is represented by reaction 1(a) and givesthe novel intermediates of this invention. In other words, the processis for preparing a compound having the formula in which R, R, R and Xare as defined comprising reacting a compound of the formula in which Rand RI are defined with a compound of the formula in which R and X areas defined.

Preferably, reaction 1(a) is carried out by reacting preferably equalmole amounts of two reactants. If an excess of either reactant is used,the reaction still proceeds but yields are reduced. The reactants can becombined in any desired manner but preferably, the reaction is run in asolvent such as THF by first preparing the salt of the oxime reactantwith an acid acceptor such as potassium t-butoxide at room temperatureand then preferably slowly adding the dichloride reactant thereto,preferably in solution with a solvent, for example, THF, at atemperature below about 15C. for control. However, the oxime reactantcan be used in place of the salt preferably in the presence of the acidacceptor. The resulting product is recovered and purified by standardprocedure. For example, the resulting product can be recovered from'thereaction mixture and purified from the reaction mixture by adding themixture to a non-polar solvent such as benzene. The benzene mixture isthen washed with water, dilute NaOH solution and'then again by water.The benzene is evaporated after the water has been removed, for example,by treatment with anhydrous MgSO to yield the purified product.

The novel intermediate compounds of this invention which are useful inpreparing the insecticidal and acaricidal compounds of this invention,for example, by reaction'l(b), heretofore described are those having theformula R r J e- 5R in which X is oxygen or sulfur; R'is alkyl havingone to eight carbon atoms, preferably branched chain or methyl, morepreferably methyl and t-butyl; R is alkyl having one to four carbonatoms, preferably methyl; R

is alkyl having one to four carbon atoms, preferably one to two carbonatoms; or alkoxy having one to four carbon atoms, preferably one to twocarbon atoms.

These intermediate compounds can be prepared according to reaction 1(a)specifically described heretofore.

The reaction, reaction [(12), is carried out by reacting preferablyequal mole amounts of the two reactants. If an excess of either reactantis used, the reaction still proceeds but yields are reduced. Thereactants can be combined in any manner, for example, thephosphoruscontaining reactant is slowly added to the phenol orthiophenol reactant in a solvent such as THF, preferably with stirring.More preferably, an alkali metal salt of the phenol or thiophenol saltis used to reduce the chance of a violent reaction. The temperature ofthe reaction is not critical, however, generally better yields areobtained by heating the reactants at reflux for a time sufficient toallow completion of the reaction. The resulting product can be recoveredfrom the reaction mixture and purified by standard procedures. Forexample, the desired reaction product can be recovered from the reactionmixture by adding the mixture to a non-polar solvent such as benzene.The benzene mixture is then washed with water, dilute NaOH solution andthen again by water. The benzene is evaporated after the water has beenremoved, for example, by treatment with anhydrous MgSO to yield thepurified product.

Preparation of the compounds of this invention, the intermediatecompounds of this invention and the process of this invention forpreparing said intermediate compounds are illustrated by the followingexamples:

EXAMPLE I O-(Acetoneoximino), ethyl, thiophosphonyl chloride 11.2 grams(0.1 moles) or potassium t butoxide is combined with 300 ml. oftetrahydrofuran in a 600 ml. beaker and 7.3 grams (0.1 moles) ofacetoneoxime is added. The mixture is stirred at room temperature for 15minutes. 16.3 grams (0.] moles) of ethyl phosphonothionic dichloride iscombined with 100 ml. of tetrahydrofuran in a 1 liter three-neck flaskfitted with a stirrer, thermometer and dropping funnel. The solution iscooled in an ice bath and stirred. The oxime salt solution is added overa period of 15 minutes at such a rate that the temperature does notexceed 15C. After the addition is complete, the resulting mixture isstirred at room temperature for 1 hour, then poured into 400 ml. ofbenzene. The benzene mixture is washed with two 300 ml. portions of H 0,dried with anhydrous MgSO. and evaporated under reduced pressure toyield 15.2 grams (76.2% of theory) of O-(acetone-oximino), ethyl,thiophosphonyl chloride. N l .5184. The compound is characterized by IRand NMR.

EXAMPLE [1 O-( Acetoneoximino), ethyl-( 4-nitrophenyl )thionophosphonate7. grams (0.0503 moles) of 4-nitrophenol is combined with 2.1 grams(0.0503 moles) of caustic and 25 mil. of water in a 500 ml. three-neckflask fitted with a stirrer, thermometer and dropping funnel. Themixture is stirred and 10 grams (0.0503 moles) of O- acetoneoximino),ethylthiophosphoryl chloride, obtained in Example l, in 200 ml. oftetrahydrofuran is added over a period of 30 minutes. The resultingmixture is stirred and heated under reflux for 2 hours, cooled andpoured into 400 ml. of benzene. The benzene mixture is washed with 200ml. of H 0, 200 ml. dilute NaOH solution, followed by two 200 ml.portions of H 0. The benzene is dried with anhydrous MgSO and evaporatedto yield 10.9 grams (72.3% of theory) of the desired compound,O-(acetoneoximine), ethyl- (4-nitrophenyl)-thiophosphonate. m.p. 82-87C.The compound is characterized by IR and NMR.

EXAMPLE 111 O-(Acetoneoximino) O-ethyl thiophosphoryl chloride 17.9grams (0.1 moles) of ethyldichlorothiophosphate is combined with 20 ml.of tetrahydrofuran in a 250 ml. three-neck flask fitted with a stirrer,thermometer and dropping funnel. The solution is stirred and cooled to10C. A solution of 9.5 grams (0.13 moles) of acetoneoxime, 4.0 grams(0.1 moles) of caustic, and 20 ml. of water is added to the stirringsolution over a period of 30 minutes. The resulting mixture is stirredfor 1 hour at 0C. and 30 mm at room temperature until the mixturebecomes neutral to pH paper. The mixture is then poured into 300 ml. ofEt O and is washed with two ml. portions of H O.,The Et O phase is driedwith anhydrous MgSO and evaporated to yield 21.4 grams (99.9% of theory)of the desired compound. N,f*.1.5037. The structure is characterized byIR and NMR.

EXAMPLE 1v C=NO C H/ z s O-( Acetoneoximino )-O-ethyl-O-(4-nitrophenyl)phosphorothioate 10.0 grams (0.0465 moles) of O-(acetoneoximino),O-ethyl thiophosphoryl chloride obtained in Example 111 is reacted with7 grams (0.0503 moles) of 4- nitrophenol and 2.1 grams (0.0503 moles) ofcaustic in the same manner as Example 11 to yield 12.6 grams (85.5% oftheory) of the desired compound. N 1.5335. Compound is characterized byNMR and IR.

EXAMPLE v O-( Acetoneoximino) O-ethylphosphorochloridate In a 600 ml.beaker, 1 1.02 grams (0.1 moles) of potassium t-butoxide is combinedwith 300 ml. of tetrahydrofuran. The mixture is stirred in an ice bathand 7.3 grams (0.1 mole) of acetoneoxime is added over a period of 5minutes. 16.3 grams (0.] mole) of ethyldichlorophosphate is combinedwith 100 ml. of tetrahydrofuran in a 1 liter three-neck flask fittedwith a dropping funnel, stirrer and thermometer. The solution is stirredand cooled in an ice bath. The oxime salt is added over a period of 15minutes at such a rate that the temperature does not exceed 15C. Afterthe addition is complete, the resulting mixture is stirred-at roomtemperature for 1 hour. 400 ml. of benzene is added and'the mixture iswashed with two 300 ml. portions of water. The benzene phase is driedwith anhydrous magnesium sulfate and evaporated under reduced pressureto yield 16.8 grams (84.3% of theory) of the desired product. N,,1.4560.The structure is confirmed by NMR. 1

EXAMPLE VI msoli cm oc a grams (0.0503 moles) of O-(acetoneoximino) O-ethyl phosphorochloridate is combined with 300 ml. of tetrahydrofuran ina 500 ml. three-neck flask fitted with a stirrer, dropping funnel,thermometer and reflux condenser. The solution is stirred and cooled to5C. in an ice bath. 7.0 grams (0.05 moles) of 4-nitrophenol, 2.1 grams(0.0503 moles) of caustic and 25 mlfof water are combined in a 50 ml.beaker. The resulting salt solution is added to the chloridate at such arate that the temperature does not exceed C. The resulting mixture isstirred at room temperature for 1 hour and is heated under reflux for 1hour. The mixture is cooled to room temperature and 400 ml. of benzeneis added. The mixture is washed in turn with 200 ml. of water. 200 ml.dilute caustic and two 200 ml. portions of water. The benzene phase isdried with anhydrous magnesium sullate and evaporated under reduce ofpressure to yield 10.5 grams (69.571 of theory) of the desired compound.N,,"" 1 .5280. The structure is confirmed by the infrared spectrum. e i

EXAMPLE v11 O-( Acetoneoximino) ethyl-S-phenylphosphonodithioate 5.5grams (0.0505 moles) of thiophenol is combined with 2.1 grams (0.0503moles) of caustic and 25 ml. of water in a 500 m1. three-neck flaskfitted with a stirrer, thermometer and dropping funnel. The mixture isstirred and 10 grams (acetoneoximino) ethylthiophosphoryl chloride,obtained in Example I, in 200 ml. tetrahydrofuran is added over a periodof 30 minutes. The resulting mixture is stirred and heated under refluxfor 2 hours. cooled and poured into 400ml. of benzene. The benzenemixture is washed with 200 ml. of water, 200 ml. of dilute causticsolution, followed by two 200 ml. portions of water. The benzene phaseis dried with anhydrous MgSO and evaporated under reduced pressure toyield 10.8 grams (79.2% of theory) of the desired compound.N,,-"-'-1.5830. The compound is characterized by IR.

EXAMPLE VIII O-(Acetoneoximino) 0-ethyl-S-phenylphosphorothioate 5.5grams (0.0505 moles) of thiophenol is'combined with 2.1 grams.(0.0503moles) of caustic and 25 ml. of water in a 500 ml. three-neck flaskfitted with a stirrer. thermometer, and dropping funnel. The mixture isstirred and 10 grams (0.0503 moles) of O- (acetoneoximino)O-ethylphosphorochloridate. tained in Example V. in 200 ml. oftetrahydrofuran is added over a period of 30 minutes. The resultingmixture is stirred and heated under reflux for two hours. cooled andpoured into 400 ml. of benzene. The benzene mixture is washed with 200ml. of water, 200 ml. of dilute caustic solution. followed by two 200ml. portions of water. The benzene phase is dried with anhydrous MgSOand evaporated under reduced pressure to yield 6.5 grams (50.5% oftheory) of the desired compound. N,,l .5642. The compound ischaracterized by IR and NMR.

The following is a table of certain selected compounds that arepreparable according to the procedure described hereto. Compound numbersare assigned to each compound and are used throughout the remainder olthe application.

(0.0503 moles) of 0- 1" CH, CH, C,H s 0 @4 10, 82-87 2 CH, CH, C,H, s oNo, 1 1-14 3 CH, CH, C,H, s o -CN 74-76 4 CH, CH, C,H, s s Q 1.5830

5 CH, CH, C,H, s 0 Cl 1.5510

6 CH, CH, C,H, s o Q-CH, 1.5342

c1 1 CH, CH, czH, s o -Cl 1.5515

8 CH, CH, C,H, s o w No, l.5614

9 (CH,),CH CH, C,H, s s Q 1.5713

10 CH, CH, C,H, s o sCH, 1.5788

1 1 CH, CH, C,H s s -Cl 1.5895

CH, 12 CH, CH, C,H, s o -C1 1.5430

13 CH, CH, 0C,H, o o 1-102 L5280 14 CH, CH, 0C,H, o 0 CH, 1.4998

15 C,H, CH, C,H, s o .Q-NO, 1.5400

16 C ,H, CH, OC2H, o o (34w 1.5030

, V v 17 CzHs CH, czH, s 0 Q0 1.5417

18 2 3 01H, 5 o -CH, 1,5284

19 C,H, CH, C,H, s 0 6-010, 1.5400

TABLE l.-Continued. J 5

Comm.p.C

d N i i r nber R R R x v R3 or NH" H3 75 (CH;.);C CH3 c 11 s C c1 1.5260

c1 76 (CH C CH3 c l-1 s 0 c1 1.5272

77 (c1-1 c c1-1 c n, 5 o 1-10 1.5300

7s (c1-1 c CH CH3 5 o @400 1.5190

79 (CH=)=C e11 e113 5 0 0-0 1.5 15

:31 so (c1-1=)3c CH CH s o c1 1.525s

s1 (CH3)3C CH3 CH 5 s l.5642

82' C113 c1-1, OC H o s 1.5642

c1= 83 CH3 CH c,1-1 s 0 1.5005

84 CH CH3 c2115 s o 1 1.5894

85 CH3 CH3 cm s s o .Q-F 1.5240

. TH: 86 CH, c11 0 5 s 0 '--so NH 1.5480

"Compound Nov 1 prepared in Example ll Compound No. 4 prepared inExample Vll Compound No. l3 prepared in Example Vl "Compound No.prepared in Example lV Compound No. 82 prepared in Example Vlll Thefollowing tests illustrate utility of the compounds as insecticides andacaricides.

INSECTICIDAL EVALUATION TESTS lected compounds as insecticides by thefollowing procedure. A stock solution containing 100 ug/ml of thetoxicant in an appropriate solvent was prepared. Aliquots of thissolution were combined with l milliliter of an acetone-peanut oilsolution in an aluminum dish and allowed to dry. The aliquots werethereto achieve desired toxicant concentration ranging from 100 ug per dishto that at which mortality was attained. The

dishes were placed in a circular cardboard cage, closed on the bottomwith cellophane and covered on top with cloth netting. Twenty-fivefemale houseflies, 3 to 5 days old, were introduced into the cage andthe percent mortality was recorded after 48 hours. The LD-SO values areexpressed in terms of ug per 25 femaleflies. The results of theseinsecticidal evaluation tests are given in Table II under HF."

In the German Cockroach (GR) tests, 10 1-month old nymphs were placed inseparate circular cardboard cages sealed on one end with cellophane andcovered by a cloth netting on theother. Aliquots of the toxi-. cants,dissolved in an appropriate solvent, were diluted in water containing0.002% of a wetting agent, Sponto 221 (a polyoxyether of alkylatedphenols blended with organic sulfonates). Test concentrations rangedfrom 0.1% downward to that at which 50% mortality was obtained. Each ofthe aqueous suspensionsofthe candidate compounds was sprayed onto theinsectsthrough j W pintobean plants or lima beanplants (Phaseolus sn) inthe primary leaf stage were used as the host plants. The young pintobean plants were infested with about 100 mites of various ages.Dispersions of candidate materi- 5 als were prepared by dissolving 0.1gram in 10 ml. of

a suitable solvent, usually'acetone. Aliquots of the llQItlcantsolutionswere suspended--in -water containing 0.002% v/v Sponto 221,polyoxyethylene ether sorbitan monolaurate, an emulsifying agent, theamount of wateribeing sufficient to give concentrations of activeingredient ranging from 0.05% to that at which 50% mortalitywasobtained. The test suspensions were then sprayed on the infested plantsto the point of run off.

After-7 days, mortalities of post-embryonic and ovithe cloth netting ymeans ofa dp y gumpereem l cidal forms were determined. The percentageof kill mortality in each case was recorded after 72 hours, and was d id b comparison i h bm l l t the LD-SO values expressed as percent oftoxicant in which had fb en Sprayed i h the candidate the aqueeus p werei These Values are pounds. The LD-SO values were calculated using well-Ported under the column GR Table known procedures. These values arereported under For testing the Salt Marsh Caterpillar, test solutions 20h columns 2 SM PE" d QSMJE f i T bl I]. were prepared in an identicalmanner and at concentrations the same as for the German-Cockroach above.Sections of bitter dock (Rumex obtu'sifolusfleaves, l SYSTEMICEVALUATION TEST 1.5 inches in length were immersed'in the test solutionsThis: test evaluates the absorption and upward 9 10 Seconds and placedwire Sqreen to translocation of the candidate systemic compound. The

e dried leaf was placed on a mo1stened p1ece of filter two-spotted mite(28M), Tetranychus urtzcae (Koch) paper in a Petri dlsh and infested wth five th1rd Instar and the Bean A hid (BA) A f b (S larvae. Mortalityof the larvae was recorded after 72 p were hours and the LD 50 valuesare ex d employed in the test for systemic act1v1ty.,

presse as percent active ingredient in the aqueous suspension 30 Youngpinto bean plants m the pnmary leaf Stage The L us Bu (LB) L h w t dwere used as host plants for the two-spotted mite. The yg g ygus espemses 6 pintobean plantswere placed in bottles containing 200 larly asthe.German Co(.:kr0ach' The caged Insects were ml. of the test solutionand held in place with cotton SPrayed h the Cahdldate compouhds atplugs. Only the roots were immersed. The test solutions t1ons rangingfrom 0.05% downward to that at which were prepared by dissolving thecompounds to be 50% mortahty was obtalned 24 and 72 w tested in asuitable solvent, usually acetone, and then :h were made to determmehvmg' and dead Insectsdiluting with distilled water. The final acetoneconcenhe LDSO (Percent) values were i fh- These tration never exceededabout 1 percent. The toxicants :e uhder the column h m Table wereinitially tested at a concentration of 10 parts per T e Insect Speclesblack heath aphld A? Aphlf million (p.p.m.). Immediately after the hostplant was f f e? was also p ye In the test l 4O placed in the testsolution it was infested with the test cdal Young hastuftlum (TropaeolumP species. Mortalities were determined after seven days. Plants,approxlmately 2 to 3 Inches were used as Young nasturtium plants wereused as the host plants host Pl f h bean p The host Ph was for the beanaphid. The host plants were transplanted infested w PP Y 75 of the P Theinto one pound of soil that had been treated with the test chemcal wasdlssohed m acetone, addgd' to water candidate compound. Immediatelyafter Planting in the which CPhtamed 3 h h of sphhtozzlr ah treated soilthe plants were infested with the aphids. emulslfymg h The Sohmoh wapphedas a spray Concentrations of toxicant in the soil ranged from 10to the infested plants. Concentrations ranged from 0.05 per pound f Soildownward until an LD leereent downward h h LDSO value was achleved valuewas obtained. Mortality was recorded after 72 These results are glven 1nTable II under the column 50 1 v g The'percentage of kill of each testspecies was determined by comparison with control plants'.placed in dis-ACARICIDAL EVALUATION TEST tilled water or untreated soil. The LD-50values were The two-spotted mite (25M), Tetranychus urticae calculated.These systemic test results are reported in (Koch), was employed intests for miticides. Young Table II under the columns BA-sys and2SM-sys.

TABLE 11 LD QVALUES I; Two-Spotted Mites Com HF GR LB SMC BA BA- PE EGGSSYS pound SYS Number ug 72 97c 7r p.p.rn. p.p.m.

As those in the art are well aware, various techniques are available forincorporating the active component or toxicant in suitable pesticidalcompositions. Thus, the pesticidal compositions can be convenientlyprepared in the form of liquids or solids, the latter preferably ashomogeneous free-flowing dusts commonly formulated by admixing theactive component with finely divided solids or carriers as exemplifiedby talc, natural clays, diatomaceous earth, various flours such aswalnut shell, wheat, soya bean, cottonseed and so forth.

Liquid compositions are also useful and normally comprise a dispersionof the toxicant in a liquid media, although it may be convenient todissolve the toxicant directly in a solvent such as kerosene, fuel oil,xylene, alkylated naphthalenes or the like and use such organicsolutions directly. However, the more common procedure is to employdispersions of the toxicant in an aqueous media and such compositionsmay be produced by forming a concentrated solution of the toxicant in asuitable organic solvent followed by dispersion in water. usually withthe aid of surface active agents. The latter, which may be the anionic,cationic, or nonionic types, are exemplified by sodium stearate,potassium oleate and other alkaline metal soaps and detergents such assodium lauryl sulfate, sodium naphthalene sulfonate, sodium alkylnaphthalene, sulfonate, methyl cellulose, fatty alcohol cthers,polyglycol fatty acid esters and other polyoxyethylene surface activeagents. The proportion of these agents commonly comprises 1 by weight ofthe pesticidal compositions although the proportion is not critical andmay be varied to suit any particular situation.

I claim:

1. A method for controlling insects comprising applying thereto aninsecticidal amount of a compound having the formula in which X issulfur, Y is oxygen, R is alkyl having one to four carbon atoms, R ismethyl, R is alkyl having one to two carbon atoms, and R is 2,4,5-trichlorophenyl.

2. The method of claim 1 in which R is methyl and R is ethyl.

3. A method for controlling insects comprising applying thereto aninsecticidal amount of a compound having the formula aml i in which X issulfur, Y is oxygen, R is alkyl having one to four carbon atoms, R ismethyl, R is alkyl having one to two carbon atoms, and R is 2,4,5-trichlorophenyl.

6. The method'of claim 5 in which'R is methyl and R is ethyl.

7. A method of controlling acarids comprising applying thereto aneffective amount of a compound having the formula in which X is.sulfur,Y is sulfur, R is alkyl having one to four carbonatoms, R is methyl, Ris alkyl having one to two carbon atoms, and R is phenyl.

8. The method-Jot claim 7 in which R is methyl and p R is ethyl.

1. A METHOD OR CONTROLLING INSECTS COMPRISING APPLYING THERETO AN INSECTICIDAL AMOUNT OF A COMPOUND HAVING THE FORMULA
 2. The method of claim 1 in which R is methyl and R2 is ethyl.
 3. A method for controlling insects comprising applying thereto an insecticidal amount of a compound having the formula
 4. The method of claim 3 in which R is methyl and R2 is ethyl.
 5. A method of controlling acarids comprising applying thereto an effective amount of a compound having the formula
 6. The method of claim 5 in which R is methyl and R2 is ethyl.
 7. A method of controlling acarids comprising applying thereto an effective amount of a compound having the formula
 8. The method of claim 7 in which R is methyl and R2 is ethyl. 